Trigger mechanism for automatic firearms.



H. BORCHARDT.

TRIGGER MECHANISM FOR AUTOMATIC FIREARMS.

APPLIOATION FILED IEB. 16,1910.

Patented Mar. 21, 1911.

4 SHEETS-SKEET l.

WITNESSES H. BORGHARDT.

TRIGGER MECHANISM FOR AUTOMATIC FIREARMS.

APPLICATION FILED r1111. 16, 1910.

987,543. Patented Mar-.21, 1911.

4 SHEBTSSHEET 2.

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g M, hBj flftm aeJ Jr H. BORGHARDT.

TRIGGER MECHANISM FOR AUTOMATIC mums.

APPLIOATION FILED FEB.16,1910

Patented Mar. 21, 1911.

4 SHEBTSSHEET 3.

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H. BORGHARDT.

TRIGGER MECHANISM FOR AUTOMATIG FIREARMS.

APPLICATION FILED FEB. 16,1910.

Patented Mar. 21, 1911.

4 SHEETS-SHEET 4.

INVEN TOR: I i itgv (fiWT/un w) TNES SE81 HUGO BORCHABDT,OFCHARLOTTENBURG, GERMANY.

TRIGGER MECHANISM FOR AUTOMATIC FIREARMS.

Specification of Letters Patent.

Patented Mar. 21, 1911.

Application filed February 16, 1910. Serial No. 544,294.

To all whom it may concern:

Be it known that I, HUGO BoRoHARoT, engineer, a citizen of the UnitedStates of America, residing at No. 31 Kantstrasse, Charlottenburg, nearBerlin, in the Kingdom of Prussia, Germany, have invented certain newand useful Improvements Relating to Trigger Mechanism for'AutomaticFirearms, of which the following is a full, clear, and exactdescription.

This invention relates to a trigger mechanism for automatic self-loadingfire-arms.

According to the invention the trigger rod or sear is not only rotatablebut also longitudinally displaceable resiliently relatively to its pointof rotation in order that when the breech returns after firing and thetrigger is still pressed the trigger rod or sear may be able to yieldand return to its engaged position when the breech moves forward.

The invention is illustrated in the accompanying drawin s in which theconstructional principle se forth above is shown embodied in a triggermechanism of the Borcha-rdt automatic pistol.

In the accompanying drawings: Figure 1 shows the loaded weapon beforefiring, that is to say with breech closed, the firing pin cocked and thetrigger in its normal position. Figs. 2 to 4 show the mechanism in, theposition which it occupies in Fig. 1, to a larger scale and in sideelevation, horizontal longitudinal section and vertical cross sectionrespectively. Figs. 5 and 6 show the mechanism in side elevation and inhorizon.- tal cross section, when the trigger has been pressed, that isto say at the point when the pressure is applied, but firing has notactually taken place and the firing pin has not been released. In Figs.7 and 8 the weapon is shown after having been fired; that is to say thefiring pin has been released and the breech block has moved rearwardunder the action of the recoil.

The application of the invention here illustrated is based upon thegeneral construction of the trigger mechanism which was described inapplicants German Patent No. 75837. The trigger sear is here a twoarmedlever i rockably mounted at the side of the breech casing, the rear endof this lever projecting into the path of the nose 1.! of the firing pin(Z under the influence of a leaf spring '5 in such manner that when thebreech block moves forward the nose d comes behind the rear end of thelever which is situated in its path, as clearly shown in Fig. 3. On itsfront end the trigger sear is provided with a resiliently mounted pin 2"upon which the nose '1 on the dog 9 connected with the trigger g orintegral therewith acts upon firing.

Now in accordance with the invention the trigger sear i isspring-controlled and longitudinally displaoeable on its pivot i owingto the fact that the eye in the lever in which the pivot engages iselongated and that the rear end of the lever which is recessed, asshown, is provided with a spiral spring i arranged therein which bearsagainst a head which closes the recess at the rear, and also against apin i Which'extends through the rear lever arm into the eye in thelever, its front end bearing against the ivot i". In the cooked orengaged position Fig. 3), the trigger sear i is kept pressed forward inopposition to the pressure of the said spring 71 so that the pivot 2'bears against the rear wall of the eye and the spring pin i against theinner inclined pressure face of the trigger nose Q1. After the triggerhas been pressed, the weapon fired, and the breech piece has sprung backinto its rearward position, the trigger sear will be the position shownin Fig. 8. Owing to the fact that the rear end of the lever has been released from the nose al the spring i which was previously compressed'isable to extend. In this extension of the spring the sear experiences arearward longitudinal displace- Went on i vot 4 that it passes from theposition Sit n in 'i ig. into the osition shown in Fig. 8. In thisposition Fig. 8) the pivot 2' bears against the front wall of the eye inthe sear; the spring pin 2' is free of the nose 9 while the rear end ofthe sear 6 extends inwardly into the path of the nosed of the firing pind so as to engage it as soon as the breech moves forwardly to close.When this occurs the operation is reversed; the nose d coming behind theend of the sear or lever again presses the sear 2' forward in oppositionto the pressure of the spring 2' so that it leaves the position shown inFig. 3 in which the spring pin 2' is situated within reach of thetrigger nose behind its oblique pressure face. Even should pressure onthe trigger be maintained, this forward movement of the sear 2' upon itsI pivot is able to take place unimpeded; in

such a case'when the sear is pressed forward by the nose d, the pin '5will merely be caused to come in front of the rear face of the triggernose g and be pressed back into its recess in the front end of the sear.Now as soon as the trigger is released and the trigger and tri ger nosereturn to initial position, the pin a is again able to move forwardlyand will then adjust itself immediately in the pressure position (Fig.3) so that firing can take place at once. Consequently wh le, whenpressure is maintained upon the trigger the weapon cannot be tired sothat unintentional firing is entirely prevented in such circumstances(that is to say when the trigger is being pressed), firing can always beagain effected as soon as the trigger. and consequently the trigger nose9 have been released for a moment so as to permit of their return toinitial position.

The method of mounting the trigger here illustrated should be noted, asit enables the pressure point to be adjusted in the simplest possiblemanner. The trigger dog (1' which carries the trigger nose Q1 issuspended upon two pivots with play in such a manner as to be movable inopposite directions; when the trigger is pressed to the pressure pointthe trigger first of all rocks about the rear and nearer of these twopivots 9 so that when the pressure point position shown in Figs. 5 and 6is reached, both pivots g and g bear upward in the pivot holes in thetrigger. When the trigger is further pressed the more distant frontpivot constitutes the axis of rotation until finally the trigger reachesthe end position shown in Figs. 7 and 8 in which the rear pivot is freedownward and upward in its pivot eye.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is:

1. In an automatic fire-arm the combination of a barrel, a breech toclose the barrel, automatic means to operate the breech, a

vfiring pin, a nose on said pin, trigger mechanism comprising a triggera pivotal and longitudinally displaceable sear, a pivot for said sear,an elongated eye in said sear in which said pivot engages, aspring-pressed pin bearing on said pivot, a spring pressed pin mountedin said sear adapted to operatively engage with the trigger, and meanswhereby said sear engages with the nose on said firing pin duringclosure of the breech and whereby said sear is displaced longitudinallyduring such closure.

2. In a fire-arm, a barrel, firing means cooperating with triggermechanism to discharge the fire-arm, said trigger mechanism including atrigger, a dog connected to said trigger, a plurality of elongated eyesin said dog, a plurality of pivots one for each eye at unequal distancesfrom said triger whereby said pivots come consecutively into operationwhen pressure is applied to the trigger.

3. In an automatic fire-arm the combination of a barrel, a breech toclose the barrel, automatic means to operate the breech, firing meanscooperating with trigger mechanism to discharge the fire-arm, saidtrigger mechanism including a trigger, a do connected to said trigger, aplurality o elongated eyes in said dog, a plurality of pivots one foreach eye at unequal distances from said trigger whereby said pivots comeconsecutively into operation when pressure is applied to the trigger.

4. In an automatic fire-arm the combination of a barrel, a breech toclose the barrel, automatic means to operate the breech, firing meanscooperating with trigger mechanism to discharge the fire-arm, saidtrigger mechanism including a trigger, a dog connected to said trigger,a plurality of elongated eyes in said dog, a plurality of pivots one foreach eye at unequal distances from said trigger whereby said pivots comeconsecutively into operation when pressure is applied to the trigger, atrigger sear or rod adapted to be controlled by and to engage with saidtrigger to engage with the firing means during closure of the breech andto be released therefrom to discharge the weapon, and means whereby saidsear may engage with the firing means during closure of the breechirrespective of the position of the trigger.

5. In an automatic fire-arm the combination of a barrel, a breech toclose the barrel, automatic means to operate the breech, firing meanscooperating with trigger mechanism to discharge the fire-arm, saidtrigger mechanism including a trigger, a dog connected to said trigger,a plurality of elongated eyes in said dog, a plurality of pivots one foreach eye at unequal distances from said tri ger whereby said pivots comeconsecutive y into operation when pressure is applied to the trigger, atrigger sear or red adapted to be controlled by and to engage with saidtrigger, to engage with the firing means during closure of the breech,and to be released therefrom to discharge the weapon, and means wherebysaid sear may engage with the firing means during closure of the breech,while pressure is applied to the trigger, and means whereby said searmay engage with said trigger when the trigger is released.

6. In an automatic firearm the combination of a barrel, a breech toclose the barrel, automatic means to operate the'breech, a firing pin, anose on said pin, trigger mechanism, said trigger mechanism including atrigger, a dog connected to said trigger, a plurality of elongated eyesin said dog, a plurality of pivots one for each eye at unequal'distancesfrom said trigger whereby said pivots come consecutively into operationwhen pressure is applied to the trigger, a rotatable and longitudinaldisplacement sear, a pivot for said sear, an elongated eye in said searin which said pivot engages, a

spring pressed pin bearing on said pivot, a spring pressed pin mountedin said sear adapted to operatively engage with the trigger, and meanswhereby said sear engages with the nose on said firing pin during HUGOBORCHARDT.

Witnesses HENRY HAsPER, WOLDEMAR HAUIT.

